Binet says that the man who has not every type of imagery almost equally well developed is only the fraction of a man. While this no doubt puts the matter too strongly, yet images do play an important part in our thinking. IMAGES SUPPLY MATERIAL FOR IMAGINATION AND MEMORY.--Imagery supplies the pictures from which imagination builds its structures. Given a rich supply of images from the various senses, and imagination has the material necessary to construct times and events long since past, or to fill the future with plans or experiences not yet reached. Lacking images, however, imagination is handicapped, and its meager products reveal in their barrenness and their lack of warmth and reality the poverty of material. Much of our memory also takes the form of images. The face of a friend, the sound of a voice, or the touch of a hand may be recalled, not as a mere fact, but with almost the freshness and fidelity of a percept. That much of our memory goes on in the form of ideas instead of images is true. But memory is often both aided in its accuracy and rendered more vital and significant through the presence of abundant imagery. IMAGERY IN THE THOUGHT PROCESSES.--Since logical thinking deals more with relations and meanings than with particular objects, images naturally play a smaller part in reasoning than in memory and imagination. Yet they have their place here as well. Students of geometry or trigonometry often have difficulty in understanding a theorem until they succeed in visualizing the surface or solid involved. Thinking in the field of astronomy, mechanics, and many other sciences is assisted at certain points by the ability to form clear and accurate images. THE USE OF IMAGERY IN LITERATURE.--Facility in the use of imagery undoubtedly adds much to our enjoyment and appreciation of certain forms of literature. The great writers commonly use all types of images in their description and narration. If we are not able to employ the images they used, many of their most beautiful pictures are likely to be to us but so many words suggesting prosaic ideas. Shakespeare, describing certain beautiful music, appeals to the sense of smell to make himself understood: ... it came o'er my ear like the sweet sound That breathes upon a bank of violets, Stealing and giving odor! _Lady Macbeth_ cries: Here's the smell of the blood still: All the perfumes of Arabia will not sweeten this little hand. Milton has _Eve_ say of her dream of the fatal apple: ... The pleasant sav'ry smell So quickened appetite, that I, methought, Could not but taste. Likewise with the sense of touch: ... I take thy hand, this hand As soft as dove's down, and as white as it. Imagine a person devoid of delicate tactile imagery, with senseless finger tips and leaden footsteps, undertaking to interpret these exquisite lines: Thus I set my printless feet O'er the cowslip's velvet head, That bends not as I tread.